1. Field of the Invention
The present invention relates to a switched reluctance motor.
2. Description of the Related Art
A switched reluctance motor including a stator and a rotor each of which is provided with a plurality of salient poles which might be opposed to each other and winding wire wound around the salient pole of the stator is conventionally known. The switched reluctance motor is configured to realize rotational movement of the rotor by magnetic attractive force generated between the salient poles of the stator and the rotor. The switched reluctance motor is disclosed in Japanese Patent Application Laid-open No. 8-205581. The switched reluctance motor of Japanese Patent Application Laid-open No. 8-205581 obtained by winding first coil (winding wire) and second coil (winding wire) around each of the salient poles of the stator gradually changes the magnetic attractive force by delaying the magnitude of a supply current (by duty ratio of rectangular voltage) to one of the first coil and the second coil from on/off of the supply current (by duty ratio of rectangular voltage) to the other of them by arbitrary angle/time. That is to say, the switched reluctance motor decreases noise and vibration by making change in impact generated by the magnetic attractive force gradual by gradually changing the magnetic attractive force.
However, since the conventional switched reluctance motor gradually changes the magnetic attractive force, this deteriorates efficiency while decreasing the noise and vibration. Furthermore, the switched reluctance motor has a room for improvement in the noise and vibration in consideration of mounting on a vehicle.
Therefore, there is a need for a switched reluctance motor capable of inhibiting the noise and vibration while ensuring desired efficiency.